With large diameter hoses for transporting fluids exemplified by marine hoses, fluids such as oil and the like are transported at high pressures and it is necessary to strictly prevent these fluids from leaking out of the hose. Therefore, with this type of fluid transport hose, efforts to enhance pressure capacity have been carried out by disposing a plurality of layers of reinforcing layers formed from organic fiber cords as a reinforcing layer on an outer side of an inner surface rubber layer having corrosion resistance with respect to fluids. While there is no possibility of a fluid immediately leaking out of the hose in the case of a partial failure of these reinforcing layers, in consideration of safety, hoses are replaced early, at a stage of initial failure of a portion of the reinforcing layers. Thus, conventionally, multiple detection means have been proposed by which leakage, accompanying failure of the reinforcing layer, of a fluid within a hose can be detected from the outside.
For example, Japanese Unexamined Patent Application Publication Nos. H05-272678A and 2001-90873A propose a hose including a reinforcing layer formed from a main pressure cord layer and an auxiliary pressure cord layer disposed on an outer side of the main pressure cord layer. The auxiliary pressure cord layer is configured so that organic fiber cords are wrapped asymmetrically with respect to a hose axial direction, resulting in a configuration by which the entire hose is twisted and deformed by the auxiliary pressure cord layer due to pressure of a fluid that has leaked internally due to a failure of the main pressure cord layer. Thus, a failure of the reinforcing layer can be externally visually recognized due to said twisting and deforming.